1. Field of the Invention
The present invention relates to a method for enhancing the hardness of a nanoimprint mold, and more particularly to a method for enhancing the hardness of a mold by a nano-indentation technique.
2. Description of the Related Art
As science and technology advance rapidly, people have increasingly higher demand on quality and convenience of life, and thus various electronic products are developed to meet customer needs, and a light, thin, low profile, compact and durable product design becomes a the tread of development of consumer products. Therefore, materials of higher hardness are used for the manufacture of these products, and a mold of higher hardness is required for enhancing the durability of the products. However, making a mold with a material of high hardness comes with a higher level of difficulty and incurs a higher cost. On the other hand, the durability is not good enough for its requirement, if materials with lower hardness and a lower cost are used for the manufacture.
A micro manufacturing process, such as photolithography plays a very important role in a semiconductor fabrication process. As related semiconductor fabrication process technologies and photolithographic equipments advance continuously, the photolithography encounters a bottleneck of the optical imaging technology since the wavelength of light exposure is reduced. To cope with the requirements of the micro manufacture and nano manufacture, the traditional photolithography has to reduce the wavelength of the light source to comply with the trend of light, thin, low profile and compact products, but the related light sources and peripheral systems are expensive and the related manufacturing processes are time consuming, and thus the traditional photolithography will encounter the difficulty for mass productions.
On the other hand, the nanoimprint technique is more convenient, simpler and easier, and such technique simply requires an imprinting mold and a transfer of a quick and repeating printing or patterning. In addition, the nanoimprint can lower costs, and the imprint technique can be applied for preparing patterns of a large area and thus greatly reduce production costs and increase productivity.
However, selecting the material for manufacturing the mold of a nanoimprint technique is still a problem. The material with high hardness used for making the mold incurs a high cost, but the material with low hardness cannot meet the requirements of the product. Additionally, in the traditional method of enhancing the surface hardness of the mold, a single diamond probe is used to imprint the mold via continuously and periodically indentations. It takes much more time to achieve the hardening phenomenon. If the hardness will be uniform, the pressure applied to the mold must be adjusted to be identical, and many variables might be existed in operating the single diamond probe.
Therefore, finding a way of lowering the cost of the mold and a way of saving time of operating the nano-indentation apparatus, and increasing the durability of the mold demands immediate attentions and feasible solutions.
In order to solve the problem with choosing materials for the mold and saving time of operating the nano-indentation apparatus, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally proposed a feasible and effective solution by utilizing nanoindentation technology to enhance the nanoimprint mold.